The invention relates to an apparatus for the filling, particularly of a liquid or solid, flowable medium into containers, particularly drums or barrels sealed with screw plugs or otherwise constructed plugs, the screw plugs preferably being covered by slipped-on safety caps.
Apparatuses for the simultaneous filling of a liquid or solid, flowable medium into receptacles, such as containers, drums, packs or the like are known in a large number of different constructional forms.
EP-A-No. 0 105 197 discloses such a filling apparatus, which comprises a pipe system with a feed pump for the supply of the medium to be filled and with filling valves connected by means of supply lines above the receptacle to be filled. In each supply line leading to the filling valves is provided a volume chamber with an impeller arranged in its interior and which is rotated by the medium flowing to the particular filling valve. The impellers of all the volume chambers are rigidly interconnected by means of a mechanical shaft connected to a breaking means controllable by means of a system pressure-dependent control means. For the control of the filling valves there is a two-stage pneumatic control cylinder, which is directly connected with at least one filling valve and is connected to the other filling valves by means of an adjusting device. A control member is provided which responds to the weight of the filled medium by means of a balance associated with one of the filling valves is provided and is connected to the control cylinder. Such a filling apparatus makes it possible to simultaneously fill several receptacles, whilst it is only necessary to measure and monitor the filling volume or weight of a single receptacle.
U.S. Pat. No. 3,548,891 discloses a plant for the simultaneous filling of several receptacles, but using dosing and filling means in a number corresponding to the number of containers to be filled, an individual filling means being associated with each of the containers to be filled. The filling connections used in this plant make it possible to fill individual containers in accordance with the filling volume and this is made possible by a filling means being associated with each individual container. However, in the case of this filling means neither the filling volume, nor the filling weight of an individual container is measured and monitored, so that the filling of the containers is not controlled by means of the filling volume or weight of an individual container. In this filling plant, the filling volume or weight of each individual container is monitored and used for controlling the filling means.
U.S. Pat. No. 3,205,920 discloses a filling apparatus making it possible to fill with liquids containers moved passed several filling valves. The containers to be filled are supplied by means of a conveyor belt, whose forward movement is disconnected if the number of containers corresponding to the number of filling valves is located under the discharge openings of the latter. At this instant a link motion places all the filling valves simultaneously on the openings of the containers to be filled and simultaneously by means of pumps the filling valves are supplied with that liquid quantity which is to be filled into the containers. In order to ensure the uniform setting down of the filling valves onto the container openings, all said filling valves are fixed to a supporting beam, which is displaceable held in vertical guides. By means of the link motion, said supporting beam can be moved up and down with the filling valves. The filling valves are connected to the pump by means of flexible hose lines. In the case of said filling apparatus, once again all the containers are simultaneously filled with liquid using filling valves and by means of which dosing is simultaneously carried out.
Drums intended to be filled with liquids are, as is known, supplied with screwed down plugs. It is therefore necessary to remove the latter and then screw them down again after filling. Thus, the drums must be precisely aligned on the feed belt or the like of the filling means, because otherwise there is a risk that the material to be filled will flow down the drum and not into the bunghole.
For closing the filling opening of a drum or the like with a device for inserting and fixing a plug in said opening, DE-A-No. 18 17 237 discloses a closing or sealing device, in which both the device for inserting the plug and also a position determining device are so fitted in spaced manner that they can be freely moved up and down, as well as in accordance with polar co-ordinates with respect to a fixed point in a plane at right angles to the upwardly and downwardly directed movement. In addition, in said known device a gripping means is provided, in order to prevent the free movement of the devices for inserting the plug and for determining the position, together with a drive means able, when the gripping means prevents the free movement of the two devices for inserting the plug and determining the position, to move said two devices only linearly and in forced manner by a distance corresponding to the spacing between the two devices. This closing device has very large dimensions.
U.S. Pat. No. 2,731,185 discloses a plug screwing-in device with a centreing and screwing head, which comprises an outer centreing ring and a screwing head displaceable therein counter to spring tension, said head being connected by means of a drive shaft with angularly moveable joints to a drive means. In the case of this plug screwing-in device the centreing ring is constructed and profiled in such a way that on screwing in a plug into the bunghole of the drum it is supported on the upper all-round rim of the bunghole connection and therefore is adapted to the dimensions and diameter of said bunghole connection.
EP-A-No. 0 065 180 discloses a plug screwing-in device for drums having a centreing and screwing head, comprising an outer centreing ring and a screwhead located in its interior and displaceable against spring tension and which is connected to its drive means by means of a drive shaft having an angularly moveable joint. This plug screwing-in device comprises a supporting frame and an upper mounting plate and a lower mounting plate on which is arranged a centreing plate, which is provided with a cross-shaped opening and whose inner wall surface bounding the opening tapers conically towards the centreing and screwing head and passes at the bottom into a vertical wall section. The internal diameter of the recess defined by the wall section is larger than the diameter of the drive shaft. In the opening is placed a correspondingly profiled moulded or shaped body with an outer wall surface tapering conically in the direction of the centreing and screwing head. At its bottom end, the shaped body carries the centreing rings supported on the drum cover plate during the plug centreing and screwing-in process and is connected by a portion located on the centreing plate to a guide plate, which is held on at least three guide bolts fixed to the lower mounting plate of the supporting frame so as to be longitudinally displaceable and pivotable against the tension of springs. The drive shaft comprises a shaft part connected to the drive means and a shaft part carrying the screwing head, the two shaft parts being interconnected by means of a universal joint.
All the filling plants operate in the same way, namely following the alignment of the container to be filled by means of a screwing means, the screw plug is screwed out of the container filling opening, picked up and placed on a conveyor belt, which runs parallel to the feed path of the container to be filled. On said conveyor means the screw plugs removed from the screwing means and placed on the conveyor belt are brought into a new position parallel to the feed movement of the containers to be filled, in which the screw plug is screwed into the filling opening of the filled container and the screwing means for the screw plugs can also participate in this forward or advance movement if no second screwing means is provided. When the screw plug has been unscrewed, then the empty container is supplied on a conveying means to a filling station and dwells therein until the container has been filled with the corresponding filling material. The filled container then passes into the screw plug screwing-in position, where the screwing means is kept ready. In this position, it is simultaneously possible to supply safety caps, which by means of a corresponding mechanism are mounted on the screw plug screwed into the filling opening of the filled container. In such a filling plant there are three work cycles, namely in the first cycle the drum is aligned and the screw plug is unscrewed from the filling opening. Following a further advance of the thus prepared container, in the second work cycle the container is filled. Following a further advance of the filled container, in a third work cycle the filling opening is sealed by means of a screw plug and optionally the safety cap is fitted. A thus constructed and functioning filling plant has relatively large dimensions, even though satisfactory working speeds are achieved. In addition, the operating efficiency of such a filling plant is dependent on the filling time and the number of work cycles. Furthermore, there is no need in the case of such filling plants to align the containers with the screwing means and the filling means in a very accurate manner. An extremely accurate alignment or orientation of the containers is only necessary for fitting the safety caps on the already screwed in screw plugs.